Effects of chronic treatment by amiodarone on transmural heterogeneity of canine ventricular repolarization in vivo: interactions with acute sotalol
| Autor: | Weissenburger J, J. Merot, Gérard Coutris, Flavien Charpentier, Jean-Marie Poirier |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Bradycardia
medicine.medical_specialty Physiology medicine.medical_treatment Action Potentials Amiodarone Antiarrhythmic agent QT interval Electrocardiography Dogs Torsades de Pointes Physiology (medical) Internal medicine medicine Animals Repolarization Drug Interactions Analysis of Variance Dose-Response Relationship Drug biology business.industry Sotalol Fissipedia Cardiac Pacing Artificial Heart biology.organism_classification Blood pressure Anesthesia Cardiology medicine.symptom Cardiology and Cardiovascular Medicine business Anti-Arrhythmia Agents medicine.drug |
| Zdroj: | Cardiovascular Research. 44:303-314 |
| ISSN: | 0008-6363 |
| DOI: | 10.1016/s0008-6363(99)00232-1 |
| Popis: | Objective: The present study was designed to examine the effects of chronic amiodarone on the different ventricular cell subtypes in situ and to evaluate its interactions with sotalol. Methods: Three groups of dogs were studied. Group I ( n =8) received no treatment. Group II ( n =7) and group III ( n =8) received, respectively, 100 and 200 mg amiodarone orally twice a day for 6 weeks to 8 months. In vivo studies were performed under halothane anesthesia 14 h after the last administration of amiodarone. Three leads ECG, femoral blood pressure and left ventricular intramural monophasic action potentials (MAP) were continuously recorded. Bradycardia was obtained by clamping the sinus node and β-blockade and the heart was driven by atrial pacing. Three weeks before the in vivo experiments, the cellular electrophysiologic properties of right ventricular tissues obtained by cardiac biopsy in six treated and six control dogs were studied with standard microelectrodes. Results: Amiodarone produced a dose-dependent decrease in plasma levels of triiodothyronine (T3; 5.9±0.4 pM in control dogs, 3.1±0.2 pM in group III, P |
| Databáze: | OpenAIRE |
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